In the past, the particles of zinc and zinc alloy which are prepared by employing atomizing method (air atomizing) have a size passing through 35-200 mesh and are formed in a potato shape.
When using such zinc and zinc alloy as a cathode active substance for alkaline batteries and filling it up into a battery, contact degree between the particles greatly influence on discharging performance of a battery.
In general, it is said that it is better to increase the surface area of zinc alloy power particles for obtaining better discharging performance, however, along with the increase of the surface area, generation of hydrogen gas due to self-discharge tends to be increased.
In order to increase the surface area of zinc alloy powder particles, a means to form the particles in a flat shape and to reduce the smoothness of the surface of the particles can be applied, however, it is presently an only way to prepare the particles into a smaller size.
Anyway, zinc alloy powder for alkaline batteries, which generates greater contact degree between the particles and generate less hydrogen gas due to self-discharge, has not been found so far.
It is an object of the present invention to provide zinc alloy powder for alkaline batteries, of which discharging performance having been improved, being suitable to use as a cathode active substance for alkaline batteries, of which particles being prepared into a flat shape and of which particles having surface with less smoothness, for aiming at improving battery performance, particularly high-rate performance.